Barcoded Indicators for Quality Management

ABSTRACT

A barcoded indicator operative to provide a machine-readable indication of exceedance of at least one threshold by at least one product quality affecting parameter, the barcoded indicator including at least a first barcode and at least a second barcode, the at least a second barcode being in a second barcode unreadable state prior to exceedance of the at least one threshold and upon exceedance of the at least one threshold the at least a first barcode becoming unreadable and generally simultaneously the at least a second barcode becoming readable.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 14/055,422, filed Oct. 16, 2013 and entitled “Barcoded Indicators For Quality Management,” which is a continuation of U.S. patent application Ser. No. 13/321,477, now U.S. Pat. No. 8,579,193, filed Jan. 17, 2012 and entitled “Barcoded Indicators For Quality Management.” U.S. patent application Ser. No. 13/321,477 is a National Phase application of PCT/IL2010/000205, filed Mar. 10, 2010 and claims priority of PCT/IL2009/000503, filed May 20, 2009, U.S. patent application Ser. No. 12/469,309, now U.S. Pat. No. 8,091,776, filed May 20, 2009, U.S. Provisional Patent Application No. 61/231,799, filed Aug. 6, 2009 and PCT/IL2009/001167, filed Dec. 9, 2009, the disclosures of which are all hereby incorporated by reference.

Reference is made to U.S. Pat. No. 7,562,811, filed Sep. 10, 2007 and entitled “System And Method For Improved Quality Management In A Product Logistic Chain”, to PCT Patent Application No. PCT/IL07/000547, filed May 6, 2007 and entitled “A System And Method For Improved Quality Management In A Product Logistic Chain”, to PCI Patent Application No. PCT/IL07/01411, filed Nov. 14, 2007 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators”, to PCT Patent Application No. PCT/IL2008/001495, filed Nov. 13, 2008 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators”, to PCT Patent Application No. PCT/IL2008/001494, filed Nov. 13, 2008 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators”, to PCT Patent Application No. PCT/IL2009/000503, filed May 20, 2009 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators” to U.S. patent application Ser. No. 12/469,309, filed May 20, 2009 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators”, to U.S. Provisional Patent Application Ser. No. 61/231,799, filed Aug. 6, 2009 and entitled “Barcoded Indicators For Quality Management” and to PCT Patent Application No. PCT/IL2009/001167, filed Dec. 9, 2009 and entitled “Barcode Indicators for Quality Management”, the disclosures of which are hereby incorporated by reference.

Priority is hereby claimed under 37 CFR 1.78(a) (1) and (2)(i) from PCT Patent Application No. PCT/IL2009/000503, filed May 20, 2009 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators”, from U.S. patent application Ser. No. 12/469,309, filed May 20, 2009 and entitled “A System And Method For Quality Management Utilizing Barcode Indicators” and from PCT Patent Application No. PCT/IL2009/001167, filed Dec. 9, 2009 and entitled “Barcode Indicators for Quality Management”, and under 37 CFR 1.78(a) (4) and (5)(i) from U.S. Provisional Patent Application Ser. No. 61/231,799, filed Aug. 6, 2009 and entitled “Barcoded Indicators For Quality Management”.

FIELD OF THE INVENTION

The present invention relates to quality management and to indicators useful in quality management.

BACKGROUND OF THE INVENTION

The following U.S. patents relate generally to the subject matter of the present application: U.S. Pat. Nos. 6,758,397, 6,009,400, 6,685,094, 7,157,048, 7,156,597 and RE 39,226.

SUMMARY OF THE INVENTION

The present invention seeks to provide improved indicators useful in quality management systems and methodologies.

There is thus provided in accordance with a preferred embodiment of the present invention a barcoded indicator operative to provide a machine-readable indication of exceedance of at least one threshold by at least one product quality affecting parameter, the barcoded indicator including at least a first barcode including at least a first set of initially uncolored, colorable areas including at least one initially uncolored colorable area, positioned at locations between bars of the first barcode when the first barcode is in a first barcode readable state prior to exceedance of the at least one threshold, and at least a second barcode including at least a second set of initially uncolored, colorable areas including at least one initially uncolored colorable area, positioned at locations of bars of the second barcode which appear only when the second barcode is in a second barcode readable state following exceedance of the at least one threshold, the at least a second barcode being in a second barcode unreadable state prior to exceedance of the at least one threshold wherein as the result of the at least a second set being uncolored, more than a single narrow barcode bar is missing from the at least a second barcode, and upon exceedance of the at least one threshold the at least a first barcode becoming unreadable as the result of coloring of at least a portion of at least one colorable area forming part of the at least a first set of colorable areas and generally simultaneously the at least a second barcode becoming readable as the result of coloring of the at least a second set of colorable areas.

Preferably, the barcode indicator includes a coloring agent located at a first location on the indicator and a coloring agent pathway operative to allow the coloring agent to move, at a rate which is at least partially a function of time, from the first location to the first and second sets of colorable areas for coloring thereof.

Additionally, the coloring agent pathway is operative to allow the coloring agent to move by diffusing from the first location to the first and the second sets of colorable areas.

Preferably, the first set of colorable areas continues to be colored following exceedance of the at least one threshold.

Preferably, the at least one threshold includes at least one time threshold.

Preferably, the at least one threshold includes at least one time and temperature threshold.

Preferably, the quality indicator is operative to provide indications of exceedance of several different thresholds.

Preferably, at least one colorable area forming part of one of the first set of colorable areas and the second set of colorable areas has a width of a single narrow barcode bar.

Preferably, colorable areas forming part of at least one of the first set of colorable areas and the second set of colorable areas become colored sequentially.

Preferably, at least one of the first set of colorable areas and the second set of colorable areas includes at least two colorable areas. Additionally, each of the first set of colorable areas and the second set of colorable areas includes at least two colorable areas.

Preferably, the barcoded indicator further including at least a third barcode including at least a third set of initially uncolored, colorable areas including at least one initially uncolored colorable area, positioned at locations of bars of the third barcode which appear only when the third barcode is in a third barcode readable state following exceedance of the at least one additional threshold, the at least a third barcode being in a third barcode unreadable state prior to exceedance of the at least one additional threshold wherein as the result of the third set of colorable areas being uncolored, more than a single narrow barcode bar is missing from the at least a third barcode, the at least a second barcode including at least a fourth set of initially uncolored, colorable areas including at least one initially uncolored colorable area, positioned at locations between bars of the at least a second barcode when the at least a second barcode is in the second barcode readable state prior k) exceedance of the at least one additional threshold, and upon exceedance of the at least one additional threshold the at least a second barcode becoming unreadable as the result of coloring of at least a portion of at least one colorable area forming part of the at least a fourth set of colorable areas and generally simultaneously the at least a third barcode becoming readable as the result of coloring of the at least a third set of colorable areas.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

FIGS. 1A-1K together are a simplified illustration of the structure and operation of an example of a quality indicator constructed and operative in accordance with a preferred embodiment of the present invention for indicating elapsed time in temperature history;

FIGS. 2A-2K together are a simplified illustration of the structure and operation of another example of a quality indicator constructed and operative in accordance with another preferred embodiment of the present invention for indicating elapsed time in temperature history;

FIGS. 3A-3K together are a simplified illustration of the structure and operation of an example of the quality indicator constructed and operative in accordance with a preferred embodiment of the present invention for indicating elapsed time in temperature history; and

FIGS. 4A-4K together are a simplified illustration of the structure and operation of another example of the quality indicator constructed and operative in accordance with another preferred embodiment of the present invention for indicating elapsed time in temperature history.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention provides changeable barcode indicators operative to provide a machine-readable, preferably barcode-reader-readable, indication of exceedance of at least one threshold by at least one product quality affecting parameter.

Barcode readers operative to read the barcode indicators and to provide output indications, and product type responsive indication interpreters operative to receive the output indications and to provide human sensible, product quality status outputs are described in U.S. Pat. No. 7,562,811 and in the publications WO/2007/129316, WO/2008/135962, WO/2009/063464 and WO/2009/063465.

The term “barcode” is used herein to refer to a machine-readable optical code. In the examples in the specification, linear, or one-dimensional barcodes are illustrated. It is appreciated that the invention may be applicable to two dimensional barcodes as well.

Each barcode standard includes rules which govern the proper reading of the barcode. A typical barcode includes start indicia representing the start of the barcode, stop indicia representing the end of the barcode and digital indicia representing digits positioned therebetween. Each digit of the barcode is indicated by a series of bars and spaces each having a predetermined width. For example, in the 2 of 5 interleaved barcode standard, each digit is indicated by two wide bars and three narrow bars. The UPC and the EAN128 barcode standards include middle indicia with different rules for indicating digits on either side of the middle indicia. Additionally, some barcode standards employ a checksum digit, which is calculated according to a mathematical formula based on the barcode symbol digits and is used as a control for the validity of the barcode.

Accordingly, a readable barcode can be rendered unreadable in several different ways. For example, the series of bars forming the start or the stop indicia can be changed by adding or deleting bars or spaces, or by changing the width thereof. Such a change can cause the barcode reader not to recognize the start or the end of the barcode symbol resulting in the barcode not being readable.

Another possibility is adding or deleting bars or spaces of the digital indicia or changing the width thereof so that a series of bars and spaces indicating a digit no longer indicate a digit according to the standard employed. Yet another possibility is making the above changes to a series of one or more bars and spaces indicating a digit such that a different digit is indicated after the change and calculating the checksum digit including the changed digit results in a checksum digit different from the checksum digit indicated in the barcode, thereby causing the barcode to become invalid. A similar change causing invalidity of the barcode can also be made to the bars indicating the checksum digit itself.

Similarly, an unreadable barcode can be rendered readable by adding or deleting bars or spaces or changing the width thereof. For example, bars forming the start or the stop indicia in a barcode where the start or the end are not properly indicated can be changed as explained above in order to properly form start or stop indicia.

Similarly, an unreadable series of bars can be made to indicate a digit by adding or deleting bars or spaces or changing the width thereof. For example, according to the 2 of 5 Interleaved barcode standard, each digit is indicated by two wide bars and three narrow bars. If, for example, a readable barcode was rendered unreadable by changing a wide bar into a narrow bar, then changing a narrow bar into a wide bar can render the barcode readable. Similarly, if a barcode is unreadable because the checksum digit does not match the other barcode digits, then the bars indicating one of the digits or the checksum digit can be changed as explained above to restore barcode validity.

The quality indicator may incorporate a product code such as an EAN (European Article Number) or a UPC code (Universal Product Code). The examples shown in the description which follows illustrate the use of an EAN code. Alternatively, the quality indicator may incorporate a 2 of 5 interleaved barcode or any other suitable barcode or readable methodology. It is appreciated that bars of one dimensional barcodes correspond to cells in Data Matrix two dimensional barcodes and instead of the “start” and “stop” indicia of one dimensional barcodes, two adjacent borders defining a “finder pattern” are used in the Data Matrix two dimensional barcodes to locate and orient the symbol.

According to a preferred embodiment of the present invention, the quality indicator includes barcodes complying with GS1 (General Specifications) standards, which are outlined at www.gs1.org. According to GS1 standards, the three left-most digits are usually assigned to a country. In Israel, the seven, nine or ten left-most digits, including the country code, represent the supplier's code and the remaining right-most digits are used by each supplier. For example, as seen in the illustrated embodiments of the present application, the three left-most digits are 729, the GS1 country code assigned to Israel. The ten left-most digits, including the country code, represent a supplier's code and the three right-most digits are changeable by the supplier and combinations thereof are used in this application for indicating exceedance of thresholds.

The quality indicator of the present invention includes at least two barcodes preferably arranged in a stacked arrangement, each barcode preferably having at least two visible states.

Preferably, generally at any given time the visible state of only one of the barcodes forming part of an indicator is machine-readable and therefore the indicator presents a single machine-readable barcode generally at any given time. Alternatively, in one or more states of the indicator all of the barcodes forming part thereof may be in visible states which are not machine-readable and the quality indicator does not present a machine-readable barcode at these one or more states.

The phrase “generally at any given time”, as defined in this application, means at all times except possibly for short time periods. Preferably, in normal operation, a short time period means a time period of less than fifteen minutes.

The barcodes forming part of an indicator of the present invention are preferably aligned such that the axes thereof are generally parallel to each other. According to an embodiment illustrated in the description and drawings of this application, the bars of one barcode do not lie in registration with the corresponding bars of another barcode but rather are slightly offset with respect to each other. Alternatively, the bars of one barcode lie in registration with the corresponding bars of another barcode.

According to a preferred embodiment of the present invention, the barcodes are juxtaposed to one another such that there is no space between the bars of one barcode and the bars of another barcode.

According to a preferred embodiment illustrated in the description and drawings of the present application, the indicator includes interposed lines which are formed between barcodes and which prevent a barcode reader from erroneously reading parts of multiple barcodes as a single barcode.

Preferably, the interposed lines appear in the same color as barcode bars forming part of the barcodes. Alternatively, the interposed lines appear in a color which prevents erroneous reading of parts of multiple barcodes as a single barcode by a barcode reader. It is appreciated that the interposed lines do not necessarily appear in a dark color and they can appear in a light color.

According to an embodiment illustrated in the description and drawings of the present application, the interposed lines extend along the entire length of the variable barcodes. It is appreciated that the interposed lines need not extend along the entire length of the variable barcodes and they may only extend along a length necessary for preventing a barcode reader from erroneously reading parts of multiple barcodes as a single barcode.

The indicator of the present invention preferably includes at least one group of colorable areas operative to become colored or uncolored at the same time, which is hereinafter referred to as a common colorable region. The common colorable region preferably includes colorable areas forming part of more than a single barcode.

The common colorable region preferably has a width of a single narrow barcode bar. Alternatively, the common colorable region is wider than a single narrow barcode bar.

According to an embodiment illustrated in the description and drawings of the present application, each barcode includes at least one additional set of colorable areas. Each additional set of colorable areas, hereinafter referred to as an additional colorable region, preferably includes at least one colorable area, forms part of a single barcode and is configured to reduce the barcode readability level of the barcode of which it forms a part when the barcode is in an unreadable state. Preferably, an additional colorable region includes more than one colorable area. Alternatively, an additional colorable region includes a single colorable area.

According to another embodiment of the present invention, at least one barcode does not include an additional colorable region.

The phrase “barcode readability level” or “BCR level” of a barcode in an unreadable state reflects the likelihood that a barcode reader will erroneously read the barcode when it is in that unreadable state. Accordingly, an unreadable barcode having a low BCR level is not likely to be erroneously read by a barcode reader.

Reference is now made to FIGS. 1A-1K, which together are a simplified illustration of the construction and operation of one embodiment of a quality indicator for indicating a combination of elapsed time and temperature. The quality indicator described in FIGS. 1A-1K is operative to provide separate indications of exceedance of two different time durations, one hour, and three and a half hours, at a temperature of at least 7 degrees Celsius.

In each of FIGS. 1A-1K, the quality indicator 100 appears both in an exploded view in the middle of the drawing and in a planar view at the bottom portion of the drawing.

As seen in the exploded view in FIGS. 1A-1K, the quality indicator, here indicated by reference numeral 100, preferably includes a barcode defining layer 102, which is preferably printed on a transparent substrate. The printing on the transparent substrate preferably defines a background area 103, which is preferably printed with black ink and overprinted with white ink, a plurality of bars 104 forming part of barcodes I, II and III which are preferably printed with black ink, and a plurality of transparent areas 105, which are preferably printed with light blue ink, such as Pantone No. 645, which has a visual appearance similar to that of the black ink overprinted with white ink. Alternatively, the background area 103 and the plurality of ban 104 are printed in such colors so as to define high contrast therebetween.

The barcodes I, II and III are preferably arranged in a stacked arrangement. The barcodes I and II are preferably separated by an interposed line 106, which is preferably printed on the transparent substrate. The interposed line 106 is preferably generally parallel to the axes of the barcodes. The barcodes II and III are preferably separated by an interposed line 107, which is preferably printed on the transparent substrate. The interposed line 107 is preferably generally parallel to the axes of the barcodes.

The interposed lines 106 and 107 are preferably printed in black ink and extend in the illustrated embodiment throughout the length of the barcodes. Alternatively, the interposed lines 106 and 107 extend as necessary to prevent a barcode reader from reading parts of barcodes I, II and III as a single barcode.

It is appreciated that barcodes I, II and III need not be positioned on the indicator in any particular order.

For the purposes of the present specification and claims, the phrase “transparent areas” is defined so as to include within its scope areas that are either transparent or translucent.

The transparent areas 105 preferably form part of six regions: a common colorable region 110 forming part of barcodes I and 1I, an additional colorable region 111 forming part of barcode I, an additional colorable region 112 forming part of barcode II, a common colorable region 113 forming part of barcodes II and III, an additional colorable region 114 forming part of barcode II and an additional colorable region 115 forming part of barcode III.

Preferably, the common colorable region 110 includes two transparent areas, transparent area 116 forming part of barcode I and transparent area 117 forming part of barcode II.

Preferably, the common colorable region 113 includes two transparent areas, transparent area 118 forming part of barcode II and transparent area 119 forming part of barcode III.

According to the embodiment illustrated in FIGS. 1A-1K, the additional colorable region 111, forming part of barcode I, appears to the right of the transparent area 116. The transparent area 116 and the transparent areas 105 which form part of the additional colorable region 111 are preferably positioned in spaces between barcode bars forming part of barcode I in its readable state, which is indicated by reference numeral 140 in the planar view of FIG. 1A.

For the purpose of the explanation which follows, the transparent areas 105 forming part of the additional colorable region 111 are grouped into two pluralities of transparent areas: 121 and 122, as illustrated in FIGS. 1A-1K.

According to the embodiment illustrated in FIGS. 1A-1K, the additional colorable region 112 forming part of barcode II appears to the left of the transparent area 117. The transparent area 117 and the transparent areas 105 which form part of the additional colorable region 112 are positioned at locations of bars which appear when barcode II is in its readable state, which is indicated by reference numeral 163 in the planar view of FIG. 1E.

For the purpose of the explanation which follows, the transparent areas 105 forming part of the additional colorable region 112 are grouped into two pluralities of transparent areas: 124 and 125, as illustrated in FIGS. 1A-1K.

According to the embodiment illustrated in FIGS. 1A-1K, the additional colorable region 114, forming part of barcode II, appears to the right of the transparent area 118. The transparent area 118 and the transparent areas 105 which form part of the additional colorable region 114 are preferably positioned in the spaces between barcode bars forming part of barcode II in its readable state, which is indicated by reference numeral 163 in the planar view of FIG. 1E.

According to the embodiment illustrated in FIGS. 1A-1K, the additional colorable region 115 forming part of barcode III appears to the left of the transparent area 119. The transparent area 119 and the transparent areas 105 which form part of the additional colorable region 115 are positioned at locations of bars which appear when barcode III is in its readable state, which is indicated by reference numeral 175 in the planar view of FIG. 1J.

Disposed behind the barcode defining layer 102 and preferably adhered thereto is a colorable element 130, such as Whatman No. 3 filter paper commercially available from Whatman International [CAT #: 1003917], which until colored is normally white. The colorable element 130 preferably extends behind the common colorable regions 110 and 113 and the additional colorable regions 111, 112, 114 and 115.

Disposed behind the barcode defining layer 102 and behind the colorable element 130 is a back layer 135. Preferably adhered to the back layer 135 rearwardly of the colorable element 130 is a temperature responsive coloring element 136, such as a pad, for example, blotting paper GB003 0.8 mm thick, commercially available from Whatman international (cat #426890), impregnated with a coloring agent, such as Sudan Black, a black color dye [CAS: 4197-25-5], dissolved to a concentration of 0.3% in 80% Oleic Acid [CAS: 112-80-1] and 20% Lauric Alcohol [CAS: 112-53-8], which freezes at 5 degrees Celsius and melts at 7 degrees Celsius.

Turning now to FIG. 1A, as can be seen in the planar view, barcode I is initially in a readable state indicated by reference numeral 140, which is typically readable by a barcode reader as 7290003804115 and barcodes II and III are in unreadable states indicated by reference numerals 141 and 142, respectively.

As can be seen in the exploded view of FIG. 1A, the transparent area 117 and the transparent areas 105 forming part of the additional colorable region 112 forming part of barcode II are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode II in its readable state are missing from barcode II. The missing plurality of barcode bars results in barcode II in the initial unreadable state 141 having a low BCR level.

As can also be seen in the exploded view of FIG. 1A, the transparent area 119 and the additional colorable region 115 forming part of barcode III are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode II in its readable state are missing from barcode III. The missing plurality of barcode bars results in barcode lit in the initial unreadable state 142 having a low BCR level.

It is appreciated that if the indicator is read by a barcode reader scanning along a line which extends across more than one barcode, for example along the line designated by reference numeral 144 which extends across barcodes I and II or along the line designated by reference numeral 145 which extends across barcodes II and III, a portion of at least one of the interposed lines 106 and 107, for example a portion of the interposed line 106 designated by reference numeral 146 or a portion of the interposed line 107 designated by reference numeral 147, is detected by the barcode reader and prevents the reading of parts of multiple barcodes, in the illustrated example parts of barcodes I and II or parts of barcodes II and III, as parts of a single barcode.

Turning to FIG. 1B, as can be seen in the exploded view, when the temperature at the quality indicator exceeds 7 degrees Celsius, such as when the temperature reaches 8 degrees Celsius, the coloring agent, indicated by reference number 150 begins to melt and be released from the coloring element 136 and begins to diffuse through the colorable element 130. The colored portions of the colorable element 130 cannot be seen through the plurality of the transparent areas 105 and, as can be seen in the planar view, barcodes I, II and III remain unchanged.

Turning to FIG. 1C, as can be seen in the exploded view, following the elapse of a certain amount of time at 8 degrees, for example 30 minutes, the coloring agent 150 continues to diffuse through the colorable element 130. As a result, portions of the colorable element 130 are visible through the plurality of transparent areas indicated by reference number 124, resulting in the appearance of a plurality of bars indicated by reference numeral 152 forming part of barcode II, as can be seen in the planar view. Barcode I remains in the readable state 140, barcode III remains in the unreadable state 142, and the changed unreadable state of barcode II is indicated by reference number 153.

The barcode bars which appear at the locations of the transparent area 117 and of the plurality of transparent areas 125 when barcode II in its readable state, indicated by reference numeral 163 in FIG. 1E, are still missing from barcode II. This missing plurality of barcode bars results in the BCR level of barcode II in the unreadable state 153 being still low.

As can be seen from the planar view of FIGS. 1B and 1C, less barcode bars are missing when barcode II is in the unreadable state 153 than when it is in the unreadable state 141. Accordingly, it is appreciated that the BCR level of barcode II in the unreadable state 153 is higher than the BCR level thereof in the unreadable state 141.

Turning to FIG. 1D, as can be seen in the exploded view, following the elapse of an additional amount of time at 8 degrees, for example another 25 minutes, the coloring agent 150 continues to diffuse through the colorable element 130. As a result, portions of the colorable element 130 are visible through the plurality of transparent areas indicated by reference number 125, resulting in the appearance of an additional plurality of bars 154 forming part of barcode II, as can be seen in the planar view. Barcode I remains in the readable state 140, barcode III remains in the unreadable state 142 and the changed unreadable state of barcode I is indicated by reference number 155. Only a single narrow barcode bar which appears at the location of the transparent area 117 when barcode I in its readable state, indicated by reference numeral 163 in FIG. 1E, is still missing from barcode II, and the missing barcode bar renders barcode II in state 155 unreadable.

It is appreciated that because only a single narrow barcode bar is missing in the unreadable state 155, the BCR level of barcode II in the unreadable state 155 is higher than that of barcode II in the unreadable states 141 and 153 described in FIGS. 1A-1C.

Turning to FIG. 1E, as can be seen in the exploded view, when a threshold is exceeded by the temperature at the indicator being at least 7 degrees Celsius for at least a predetermined cumulative amount of time, such as 8 degrees Celsius for a total of at least one hour, the coloring agent 150 diffuses through the colorable element 130, such that portions of the colorable element 130 are visible through the common colorable region 110, including the transparent areas indicated by reference numerals 116 and 117.

As a result of portions of the colorable element 130 being visible through the transparent area indicated by reference numeral 116, a space indicated by reference numeral 160, which is located between bars of barcode I in its readable state, is filled in, thereby causing barcode I to assume an unreadable state 161, as can be seen in the planar view.

As a result of portions of the colorable element 130 being visible through the transparent area indicated by reference numeral 117, a single narrow barcode bar indicated by reference numeral 162 appears in barcode II, thereby causing barcode II to assume a readable state 163, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804139.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode I in its readable state is filled in, the BCR level of barcode I in the unreadable state 161 is high, similar to the BCR level of barcode II in the unreadable state 155 described in FIG. 1D.

Turning to FIG. 1F, as can be seen in the exploded view, if the temperature is at least 7 degrees Celsius for an additional amount of time, for example 8 degrees Celsius for an additional 30 minutes, the coloring agent 150 continues to diffuse through the colorable element 130, such that portions of the colorable element 130 are visible through the transparent areas indicated by reference numeral 121. As a result, a plurality of spaces indicated by reference numeral 165 located between the bars of barcode I in its readable state is filled in, as can be seen in the planar view. Barcode II remains in the readable state 163, barcode III remains in the unreadable state 142 and barcode I assumes a further unreadable state, indicated by reference number 166. As a result of the coloring of the plurality of spaces 165, the BCR level of barcode I in the unreadable state 166 decreases.

As can be seen from the planar view of FIGS. 1E and 1F, more spaces are filled in between bars of barcode I in the unreadable state 166 than in the unreadable state 161. Accordingly, it is appreciated that the BCR level of barcode I is lower in the unreadable state 166 than in the unreadable state 161.

Turning to FIG. 1G, as can be seen in the exploded view, if the temperature is at least 7 degrees Celsius for an additional amount of time, for example 8 degrees Celsius for an additional 30 minutes, the coloring agent 150 continues to diffuse through the colorable element 130, such that portions of the colorable element 130 are visible through the transparent areas indicated by reference numeral 122. As a result, an additional plurality of spaces indicated by reference numeral 167, located between the bars of barcode I in its readable state, appears colored, as can be seen in the planar view. Barcode II remains in the readable state 163, barcode III remains in the unreadable state 142 and barcode I assumes a further unreadable state 168. As a result of the coloring of the additional plurality of spaces 167, the BCR level of barcode I in the unreadable state 168 further decreases.

As can be seen from the planar view of FIGS. 1F and 1G, more spaces are filled in between barcode bars of barcode I in the unreadable state 168 than in the unreadable state 166. Accordingly, the BCR level of barcode I is lower in the unreadable state 168 than in the unreadable state 166.

Turning to FIG. 1H, as can be seen in the exploded view, if the temperature is at least 7 degrees Celsius for an additional amount of time, for example 8 degrees Celsius for an additional one hour, the coloring agent 150 continues to diffuse through the colorable element 130. The additional colored portions of the colorable element 130 are not seen through the plurality of the transparent areas 105 and, as can be seen in the planar view, barcodes I, II and III remain unchanged.

As can be seen in the exploded view of FIG. 1H, the transparent area 119 and the additional colorable region 115 forming part of barcode III are still uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode III in its readable state, indicated by reference numeral 175 in FIG. 1J, are still missing from barcode III. The missing barcode bars result in barcode III in the unreadable state 142 having a low BCR level.

Turning to FIG. 1I, as can be seen in the exploded view, following the elapse of an additional amount of time at 8 degrees, for example another 8 minutes, the coloring agent 150 continues to diffuse through the colorable element 130. As a result, portions of the colorable element 130 are visible through the plurality of transparent areas 105 forming part of the additional colorable region indicated by reference numeral 115, resulting in the appearance of a plurality of bars 170 forming part of barcode III, as can be seen in the planar view. Barcode I remains in the unreadable state 168, barcode II remains in the readable state 163 and the changed unreadable state of barcode III is indicated by reference number 171. Only a portion of a barcode bar which appears at the location of the transparent area 119 when barcode III in its readable state, the portion having a width of a single narrow barcode bar, is still missing from barcode III, and the missing barcode bar portion renders barcode III in state 171 unreadable.

It is appreciated that because only a portion of a barcode bar is missing in the unreadable state 171, the portion having a width of a single narrow barcode bar, the BCR level of barcode III in the unreadable state 171 is higher than that of barcode III in the unreadable state 142 described in FIG. 1A-1H.

Turning to FIG. 1J, as can be seen in the exploded view, when a second threshold is exceeded by the temperature at the indicator being at least 7 degrees Celsius for at least a second predetermined cumulative amount of time, such as 8 degrees Celsius for a total of at least three and a half hours, the coloring agent 150 diffuses through the colorable element 130, such that portions of the colorable element 130 are visible through the common colorable region 113, including the transparent areas indicated by reference numerals 118 and 119.

As a result of portions of the colorable element 130 being visible through the transparent area indicated by reference numeral 118, a space indicated by reference numeral 172, which is located between bars of barcode II in its readable state, is filled in, thereby causing barcode II to assume an unreadable state 173, as can be seen in the planar view.

As a result of portions of the colorable element 130 being visible through the transparent area indicated by reference numeral 119, a portion of a barcode appears in barcode III, the portion being indicated by reference numeral 174 and having a width of a single narrow barcode bar. As a result, barcode III assumes a readable state 175, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804122.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode II in its readable state is filled in, the BCR level of barcode II in the unreadable state 173 is high, similar to the BCR level of barcode III in the unreadable state 171 described in FIG. 1I.

Turning to FIG. 1K, as can be seen in the exploded view, if the temperature is at least 7 degrees Celsius for an additional amount of time, for example 8 degrees Celsius for an additional 30 minutes, the coloring agent 150 continues to diffuse through the colorable element 130, such that portions of the colorable element 130 are visible through the transparent areas 105 forming part of the additional colorable region indicated by reference number 114. As a result, a plurality of spaces 176, located between the bars of barcode II in its readable state, is filled in, as can be seen in the planar view. Barcode I remains in the unreadable state 168, barcode III remains in the readable state 175 and barcode II assumes a further unreadable state, indicated by reference numeral 177. The plurality of spaces 176 becoming filled in causes the BCR level of barcode II in the unreadable state 177 to decrease.

As can be seen from the planar view of FIGS. 1J and 1K, more spaces are filled in between barcode bars of barcode II in the unreadable state 177 than in the unreadable state 173. Accordingly, it is appreciated that the BCR level of barcode II is lower in the unreadable state 177 than in the unreadable state 173.

It is appreciated that if the temperature drops below 7 degrees Celsius the coloring agent 150 continues to diffuse through the colorable element 130. If, after the temperature reaches 7 degrees Celsius, the temperature drops below 5 degrees Celsius, then the coloring agent ISO becomes solid and diffusion thereof through the colorable element 130 is suspended until the temperature again reaches 7 degrees Celsius.

Reference is now made to FIGS. 2A-2K, which together are a simplified illustration of the construction and operation of one embodiment of a quality indicator for indicating a combination of elapsed time and temperature. The quality indicator described in FIGS. 2A-2K is operative to provide separate indications of exceedance of two different temperatures: 7 degrees Celsius and 10 degrees Celsius, for a time duration of at least one hour at each temperature.

In each of FIGS. 2A-2K, the quality indicator 200 appears both in an exploded view in the middle of the drawing and in a planar view at the bottom portion of the drawing.

As seen in the exploded view in FIGS. 2A-2K, the quality indicator, here indicated by reference number 200, preferably includes a barcode defining layer 202, which is preferably printed on a transparent substrate. The printing on the transparent substrate preferably defines a background area 203, which is preferably printed with black ink and overprinted with white ink, a plurality of bars 204 forming part of barcodes IV, V and VI which are preferably printed with black ink, and a plurality of transparent areas 205, which are preferably printed with light blue ink, such as Pantone No. 645, which has a visual appearance similar to that of the black ink overprinted with white ink. Alternatively, the background area 203 and the plurality of bars 204 are printed in such colors so as to define high contrast therebetween.

The barcodes IV, V and VI are preferably arranged in a stacked arrangement. The barcodes IV and V are preferably separated by an interposed line 206, which is preferably printed on the transparent substrate. The interposed line 206 is preferably generally parallel to the axes of the barcodes. The barcodes V and VI are preferably separated by an interposed line 207, which is preferably printed on the transparent substrate. The interposed line 207 is preferably generally parallel to the axes of the barcodes.

The interposed lines 206 and 207 are preferably printed in black ink and extend in the illustrated embodiment throughout the length of the barcodes. Alternatively, the interposed lines 206 and 207 extend as necessary to prevent a barcode reader from reading parts of barcodes IV, V and VI as a single barcode.

It is appreciated that barcodes IV, V and VI need not be positioned on the indicator in any particular order.

The transparent areas 205 preferably form part of six regions: a common colorable region 210 forming part of barcodes IV and V, an additional colorable region 211 forming part of barcode IV, an additional colorable region 212 forming part of barcode V, a common colorable region 213 forming part of barcode s V and VI, an additional colorable region 214 forming part of barcode V and an additional colorable region 215 forming part of barcode VI.

Preferably, the common colorable region 210 includes two transparent areas, transparent area 216 forming part of barcode IV and transparent area 217 forming part of barcode V.

Preferably, the common colorable region 213 includes two transparent areas, transparent area 218 forming part of barcode V and transparent area 219 forming part of barcode VI.

According to the embodiment illustrated in FIGS. 2A-2K, the additional colorable region 211, forming part of barcode IV, appears to the right of the transparent area 216. The transparent area 216 and the transparent areas 205 which form part of the additional colorable region 211 are preferably positioned in the spaces between barcode bars forming part of barcode IV in its readable state, which is indicated by reference numeral 240 in the planar view of FIG. 2A.

For the purpose of the explanation which follows, the transparent areas 205 forming part of the additional colorable region 211 are grouped into two pluralities of transparent areas: 221 and 222, as illustrated in FIGS. 2A-2K.

According to the embodiment illustrated in FIGS. 2A-2K, the additional colorable region 212 forming part of barcode V appears to the left of the transparent area 217. The transparent area 217 and the transparent areas 205 which form part of the additional colorable region 212 are positioned at locations of bars which appear when barcode V is in its readable state, which is indicated by reference numeral 263 in the planar view of FIG. 2E.

For the purpose of the explanation which follows, the transparent areas 205 forming part of the additional colorable region 212 are grouped into two pluralities of transparent areas: 224 and 225, as illustrated in FIGS. 2A-2K.

According to the embodiment illustrated in FIGS. 2A-2K, the additional colorable region 214, forming part of barcode V, appears to the left of the transparent area 218. The transparent area 218 and the transparent areas 205 which form part of the additional colorable region 214 are preferably positioned in the spaces between barcode bars forming part of barcode V in its readable state, which is indicated by reference numeral 263 in the planar view of FIG. 2E.

According to the embodiment illustrated in FIGS. 2A-2K, the additional colorable region 215 forming part of barcode VI appears to the right of the transparent area 219. The transparent area 219 and the transparent areas 205 which form part of the additional colorable region 215 are positioned at locations of bars which appear when barcode VI is in its readable state, which is indicated by reference numeral 275 in the planar view of FIG. 2J.

Disposed behind the barcode defining layer 202 and preferably adhered thereto is a colorable element 230, such as Whatman No. 3 filter paper commercially available from Whatman International [CAT #: 1003917], which until colored is normally white. The colorable element 230 preferably extends behind the common colorable region 210 and the additional colorable regions 211 and 212.

Also disposed behind the barcode defining layer 202 and preferably adhered thereto is an additional colorable element 232, such as Whatman No. 3 filter paper commercially available from Whatman International [CAT #: 1003917], which until colored is normally white. The colorable element 232 is preferably adjacent the colorable element 230 and preferably extends behind the common colorable region 213 and the additional colorable regions 214 and 215.

It is appreciated that instead of including two separate colorable elements, an indicator according to the present invention can include a single colorable element separated into two portions by a separator made of a material which is impermeable to ink, such as varnish.

Disposed behind the barcode defining layer 202 and behind the colorable elements 230 and 232 is a back layer 235.

Preferably adhered to the back layer 235 rearwardly of the colorable element 230 is a temperature responsive coloring element 236, such as a pad, for example, blotting paper GB003 0.8 mm thick, commercially available from Whatman international (cat #426890), impregnated with a coloring agent, such as Sudan Black, a black color dye [CAS: 4197-25-5], dissolved to a concentration of 0.3% in 80% Oleic Acid [CAS: 112-80-1] and 20% Laurie Alcohol [CAS: 112-53-8], which freezes at 5 degrees Celsius and melts at 7 degrees Celsius.

Preferably also adhered to the back layer 235 rearwardly of the colorable element 232 is a temperature responsive coloring element 238, such as a pad, for example, blotting paper GB003 0.8 mm thick, commercially available from Whatman international (cat #426890), impregnated with a coloring agent, such as Sudan Black, a black color dye [CAS: 4197-25-5], dissolved to a concentration of 0.3% in 100% Decyl Decanoate [CAS: 1654-86-0], which freezes at 9 degrees Celsius and melts at 10 degrees Celsius.

Turning now to FIG. 2A, as can be seen in the planar view, barcode IV is initially in a readable state indicated by reference numeral 240, which is typically readable by a barcode reader as 7290003804115 and barcodes V and VI are in unreadable states indicated by reference numerals 241 and 242, respectively.

As can be seen in the exploded view of FIG. 2A, the transparent area 217 and the transparent areas 205 forming part of the additional colorable region 212 forming part of barcode V are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode V in its readable state are missing from barcode V. The missing plurality of barcode bars results in barcode V in the initial unreadable state 241 having a low BCR level.

As can also be seen in the exploded view of FIG. 2A, the transparent area 219 and the additional colorable region 215 forming part of barcode VI are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode VI in its readable state are missing from barcode VI. The missing plurality of barcode bars results in barcode VI in the initial unreadable state 242 having a low BCR level.

It is appreciated that if the indicator is read by a barcode reader scanning along a line which extends across more than one barcode, for example along the line designated by reference numeral 244 which extends across barcodes IV and V or along the line designated by reference numeral 245 which extends across barcodes V and VI, a portion of at least one of the interposed lines 206 and 207, for example a portion of the interposed line 206 designated by reference numeral 246 or a portion of the interposed line 207 designated by reference numeral 247, is detected by the barcode reader and prevents the reading of parts of multiple barcodes, in the illustrated example parts of barcodes IV and V or parts of barcodes V and VI, as parts of a single barcode.

Turning to FIG. 21 , as can be seen in the exploded view, when the temperature at the quality indicator exceeds 7 degrees Celsius, such as when the temperature reaches 8 degrees Celsius, the coloring agent, indicated by reference numeral 250 begins to melt and be released from the coloring element 236 and begins to diffuse through the colorable element 230. The colored portions of the colorable element 230 cannot be seen through the plurality of the transparent areas 205 and, as can be seen in the planar view, barcodes IV, V and VI remain unchanged.

Turning to FIG. 2C, as can be seen in the exploded view, following the elapse of a certain amount of time at 8 degrees, for example 30 minutes, the coloring agent 250 continues to diffuse through the colorable element 230. As a result, portions of the colorable element 230 are visible through the plurality of transparent areas indicated by reference numeral 224, resulting in the appearance of a plurality of bars indicated by reference numeral 252 forming part of barcode V, as can be seen in the planar view. Barcode IV remains in the readable state 240, barcode VI remains in the unreadable state 242, and the changed unreadable state of barcode V is indicated by reference number 253.

The barcode bars which appear at the locations of the transparent area 217 and of the plurality of transparent areas 225 when barcode V in its readable state, indicated by reference numeral 263 in FIG. 2E, are still missing from barcode V. This missing plurality of barcode bars results in the BCR level of barcode V in the unreadable state 253 being still low.

As can be seen from the planar view of FIGS. 2B and 2C, less barcode bars are missing when barcode V is in the unreadable state 253 than when it is in the unreadable state 241. Accordingly, it is appreciated that the BCR level of barcode V in the unreadable state 253 is higher than the BCR level thereof in the unreadable state 241.

Turning to FIG. 2D, as can be seen in the exploded view, following the elapse of an additional amount of time at 8 degrees, for example another 25 minutes, the coloring agent 250 continues to diffuse through the colorable element 230. As a result, portions of the colorable element 230 are visible through the plurality of transparent areas indicated by reference numeral 225, resulting in the appearance of an additional plurality of bars 254 forming part of barcode V, as can be seen in the planar view. Barcode IV remains in the readable state 240, barcode VI remains in the unreadable state 242 and the changed unreadable state of barcode V is indicated by reference number 255. Only a single narrow barcode bar which appears at the location of the transparent area 217 when barcode V in its readable state, indicated by reference numeral 263 in FIG. 2E, is still missing from barcode V, and the missing barcode bar renders barcode V in state 255 unreadable.

It is appreciated that because only a single barcode bar is missing in the unreadable state 255, the BCR level of barcode V in the unreadable state 255 is higher than that of barcode V in the unreadable states 241 and 253 described in FIGS. 2A-2C.

Turning to FIG. 2E, as can be seen in the exploded view, when a threshold is exceeded by the temperature at the indicator being at least 7 degrees Celsius for at least a predetermined cumulative amount of time, such as 8 degrees Celsius for a total of at least one hour, the coloring agent 250 diffuses through the colorable element 230, such that portions of the colorable element 230 are visible through the common colorable region 210, including the transparent areas indicated by reference numerals 216 and 217.

As a result of portions of the colorable element 230 being visible through the transparent area indicated by reference numeral 216, a space indicated by reference numeral 260, which is located between bars of barcode IV in its readable state, is filled in, thereby causing barcode IV to assume an unreadable state 261, as can be seen in the planar view.

As a result of portions of the colorable element 230 being visible through the transparent area indicated by reference numeral 217, a single barcode bar indicated by reference numeral 262 appears in barcode V, thereby causing barcode V to assume a readable state 263, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804139.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode IV in its readable state is filled in, the BCR level of barcode IV in the unreadable state 261 is high, similar to the BCR level of barcode V in the unreadable state 255 described in FIG. 2D.

Turning to FIG. 2F, as can be seen in the exploded view, if the temperature is at least 7 degrees Celsius for an additional amount of time, for example 8 degrees Celsius for an additional 30 minutes, the coloring agent 250 continues to diffuse through the colorable element 230, such that portions of the colorable element 230 are visible through the transparent areas indicated by reference numeral 221. As a result, a plurality of spaces indicated by reference numeral 265 located between the bars of barcode IV in its readable state are filled in, as can be seen in the planar view. Barcode V remains in the readable state 263, barcode VI remains in the unreadable state 242 and barcode IV assumes a further unreadable state, indicated by reference number 266. As a result of the plurality of spaces 265 becoming filled in, the BCR level of barcode IV in the unreadable state 266 decreases

As can be seen from the planar view of FIGS. 2E and 2F, more spaces are filled in between barcode bars of barcode IV in the unreadable state 266 than in the unreadable state 261. Accordingly, it is appreciated that the BCR level of barcode IV is lower in the unreadable state 266 than in the unreadable state 261.

Turning to FIG. 2G, as can be seen in the exploded view, if the temperature is at least 7 degrees Celsius for an additional amount of time, for example 8 degrees Celsius for an additional 30 minutes, the coloring agent 250 continues to diffuse through the colorable element 230, such that portions of the colorable element 230 are visible through the transparent areas indicated by reference number 222. As a result, an additional plurality of spaces indicated by reference numeral 267, located between the bars of barcode IV in its readable state, are filled in, as can be seen in the planar view. Barcode V remains in the readable state 263, barcode VI remains in the unreadable state 242 and barcode IV assumes a further unreadable state 268. As a result of the additional plurality of spaces 267 becoming filled in, the BCR level of barcode IV in the unreadable state 268 further decreases.

As can be seen from the planar view of FIGS. 2F and 20 , more spaces are filled in between barcode bars of barcode IV in the unreadable state 268 than in the unreadable state 266. Accordingly, the BCR level of barcode IV is lower in the unreadable state 268 than in the unreadable state 266.

It is appreciated that if the temperature drops below 7 degrees Celsius, the coloring agent 250 continues to diffuse through the colorable element 230. If, at any time after the temperature reaches 7 degrees Celsius, the temperature drops below 5 degrees Celsius, then the coloring agent 250 becomes solid and diffusion thereof through the colorable element 230 is suspended until the temperature again reaches 7 degrees Celsius.

Turning to FIG. 211 , as can be seen in the exploded view, when the temperature at the quality indicator exceeds 10 degrees Celsius, such as when the temperature reaches 12 degrees Celsius, the coloring agent, indicated by reference number 269 begins to melt and be released from the coloring element 238 and begins to diffuse through the colorable element 232. The colored portions of the colorable element 232 cannot be seen through the plurality of the transparent areas 205 and, as can be seen in the planar view, barcodes IV, V and VI remain unchanged.

As can be seen in the exploded view of FIG. 21 , the transparent area 219 and the additional colorable region 215 forming part of barcode VI are still uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode VI in its readable state, indicated by reference numeral 275 in FIG. 2J, are still missing from barcode VI. The missing barcode bars result in barcode VI in the unreadable state 242 having a low BCR level.

It is appreciated that if the temperature increases above a second predetermined temperature before exceedance of a first threshold, which includes a first predetermined time duration at a first predetermined temperature, the coloring agent responsive to the second predetermined temperature melts and starts to be released from the corresponding coloring element before coloring of the common colorable region which is operative to indicate the exceedance of the first threshold. For example, in the embodiment illustrated in FIGS. 2A-2K, if the temperature exceeds 10 degrees Celsius before the exceedance of one hour at a temperature of at least 7 degrees Celsius, the coloring agent 269 melts and starts to be released from the coloring element 238, before the common colorable region 210 is colored by the coloring agent 250.

Turning to FIG. 21 , as can be seen in the exploded view, following the elapse of a certain amount of time at 12 degrees, for example 55 minutes, the coloring agent 269 continues to diffuse through the colorable element 232. As a result, portions of the colorable element 232 are visible through the plurality of transparent areas 205 forming part of the additional colorable region indicated by reference number 215, resulting in the appearance of a plurality of bars 270 forming part of barcode VI, as can be seen in the planar view. Barcode IV remains in the unreadable state 268, barcode V remains in the readable state 263 and the changed unreadable state of barcode VI is indicated by reference number 271. Only a single narrow barcode bar, which appears at the location of the transparent area 219 when barcode VI in its readable state, is still missing from barcode VI, and the missing barcode bar renders barcode VI in state 271 unreadable.

It is appreciated that because only a single narrow barcode bar is missing in the unreadable state 271, the BCR level of barcode VI in the unreadable state 271 is higher than that of barcode VI in the unreadable state 242 described in FIG. 2A-2H.

Turning to FIG. 2J, as can be seen in the exploded view, when a second threshold is exceeded by the temperature at the indicator being at least 10 degrees Celsius for at least a predetermined cumulative amount of time, such as 12 degrees Celsius for a total of at least one hour, the coloring agent 269 diffuses through the colorable element 232, such that portions of the colorable element 232 are visible through the common colorable region 213, including the transparent areas indicated by reference numerals 218 and 219.

As a result of portions of the colorable element 232 being visible through the transparent area indicated by reference numeral 218, a space indicated by reference numeral 272, which is located between bars of barcode V in its readable state, is filled in thereby causing barcode V to assume an unreadable state 273, as can be seen in the planar view.

As a result of portions of the colorable element 232 being visible through the transparent area indicated by reference numeral 219, a single narrow barcode bar indicated by reference numeral 274 appears in barcode VI, thereby causing barcode VI to assume a readable state 275, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804122.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode V in its readable state is filled in, the BCR level of barcode V in the unreadable state 273 is high, similar to the BCR level of barcode VI in the unreadable state 271 described in FIG. 21 .

It is appreciated that since the distance between the common colorable region 213 and the coloring element 238 is at least equal to the distance between the common colorable region 210 and the coloring element 236, the common colorable region 213 will not become colored prior to the coloring of the common colorable region 210. Alternatively, the colorable elements 230 and 232 are made from different materials such that diffusion along the colorable element 232 is slower than diffusion along the colorable element 230.

According to an embodiment of the present invention, the indicator of the present invention can be useful to indicate the exceedance of thresholds that are not always exceeded in the same order. For example, the indicator can be used to indicate the exceedance of a first threshold and a second threshold, wherein the first threshold includes a temperature lower than the temperature of the second threshold but a time duration longer than the time duration of the second threshold.

According to this embodiment, in the indicator presented in FIGS. 2A-2K, an additional colorable area is added in barcode IV such that both barcodes IV and V become unreadable in response to exceedance of the threshold which is more likely to be indicated second, for example the second threshold described above, which includes the higher temperature.

In accordance with this embodiment, if the first threshold is exceeded before exceedance of the second threshold, exceedance of the first threshold is indicated by barcode IV becoming unreadable and by barcode V becoming readable. Exceedance of the second threshold is indicated by barcode V becoming unreadable and by barcode VI becoming readable. Barcode IV, which becomes unreadable following the exceedance of the first threshold, is still unreadable regardless of the additional colorable region.

However, if the first threshold is exceeded following exceedance of the second threshold, exceedance of the first threshold is not indicated because following exceedance of the second threshold both barcodes IV and V become unreadable.

In accordance with another embodiment of the present invention, the colorable element is not separated into two portions, and indication of exceedance of the second threshold can also result from exceedance of a second time duration at or above the predetermined temperature of the first threshold.

Turning to FIG. 2K, as can be seen in the exploded view, if the temperature is at least 10 degrees Celsius for an additional amount of time, for example 12 degrees Celsius for an additional 30 minutes, the coloring agent 269 continues to diffuse through the colorable element 232, such that portions of the colorable element 232 are visible through the transparent areas 205 forming part of the additional colorable region indicated by reference number 214. As a result, a plurality of spaces 276, located between the bars of barcode V in its readable state, is filled in, as can be seen in the planar view. Barcode IV remains in the unreadable state 268, barcode VI remains in the readable state 275 and barcode V assumes a further unreadable state, indicated by reference numeral 277. As a result of the plurality of spaces 276 becoming filled in, the BCR level of barcode V in the unreadable state 277 decreases

As can be seen from the planar view of FIGS. 23 and 2K, more spaces are filled in between barcode bars of barcode V in the unreadable state 277 than in the unreadable state 273. Accordingly, it is appreciated that the BCR level of barcode V is lower in the unreadable state 277 than in the unreadable state 273.

It is appreciated that if the temperature drops below 10 degrees Celsius the coloring agent 269 continues to diffuse through the colorable element 232. If, after the temperature reaches 10 degrees Celsius, the temperature drops below 9 degrees Celsius, then the coloring agent 269 becomes solid and diffusion thereof through the colorable element 232 is suspended until the temperature again reaches 10 degrees Celsius.

In the embodiment described in FIGS. 2A-2K, the coloring agent 269 moves along the coloring element 232 from right to left and therefore the additional colorable region 214, forming part of barcode V, appears to the left of the transparent area 218 and the additional colorable region 215, forming part of barcode VI, appears to the right of the transparent area 219. Alternatively, the coloring agent 269 moves along the coloring element 232 from left to right, and then the additional colorable region 214 appears to the right of the transparent area 218 and the additional colorable region 215 appears to the left of the transparent area 219.

The phrase “more than a single narrow barcode bar” means more than one barcode bar, the barcode bars being narrow or wide or more than a portion of a wide barcode bar, the portion being of the same width as a narrow barcode bar.

According to the embodiment illustrated in FIGS. 1A-2K, the colorable areas forming part of the additional colorable region and the common colorable region become colored sequentially. Alternatively, the colorable areas forming part of the additional colorable region and of the common colorable region become colored generally simultaneously.

The phrase “generally simultaneously”, as defined in this application, means within a short time period.

It is appreciated that instead of being initially uncolored and becoming colored, a colorable area can be initially colored and become uncolored.

Preferably, as colorable areas become colored, barcode bars or portions thereof appear and spaces between barcodes or portions thereof become filled in. Alternatively, as colorable areas become colored, barcode bars or portions thereof disappear and spaces or portions thereof appear between barcode bars.

It is further appreciated that the quality indicator may be operative to provide an indication of exceedance only following actuation thereof. Alternatively, as illustrated in the description and drawings of this application, the quality indicator may be operative to provide an indication of exceedance without actuation.

According to a preferred embodiment of the present invention barcodes forming part of a quality indicator are each capable of indicating any numerical or alphanumerical sequence. Additionally or alternatively, barcodes forming part of a quality indicator are each capable of complying with any suitable barcode standard, including but not limited to EAN, UPC, 2 of 5 Interleaved, code39, code 39 extended, code 93, code 93 extended, code 128, code 128 A, B and C, ISBN, Code bar and Data Matrix. Accordingly, different barcodes forming part of the same quality indicator can comply with different barcode standards. For example, a quality indicator can include a first barcode complying with the EAN13 standard and a second barcode complying with the 2 of 5 Interleaved standard. Consequently, if the barcode reader of a checkout scanner is operative to read only the EAN13 barcode standard, then, once the first barcode becomes unreadable, the indicator no longer presents a readable barcode to the checkout scanner. However, the indicator is still readable by a barcode reader operative to read the 2 of 5 Interleaved standard.

Applicant's U.S. application Ser. No. 12/469,309, filed May 20, 2009, which is hereby incorporated by reference, discloses a quality indicator which is intended to present a single readable barcode generally at any given time.

The phrase “generally simultaneously”, as defined in this application, means within a short time period.

Preferably, in normal operation, a short time period means a time period of less than fifteen minutes.

The quality indicator of U.S. Ser. No. 12/469,309 includes at least two variable barcodes, such as a first barcode and a second barcode, preferably arranged in a stacked arrangement. Each of the at least two variable barcodes includes at least one colorable area and has at least two visible states. One of the colorable areas in the first barcode is operative to become colored or uncolored at the same time as one of the colorable areas of the second barcode. The coloring or the uncoloring occurs, for example, upon exceedance of a time in temperature threshold.

In U.S. Ser. No. 12/469,309, a group of colorable areas which are operative to become colored or uncolored at the same time is referred to as a colorable common area.

According to an embodiment disclosed on page 14, paragraph [0051] of U.S. Ser. No. 12/469,309, the coloring of the colorable common area which forms part of the first and the second barcodes in a quality indicator causes the visible state of the first barcode, which is initially readable, to become unreadable and, at the same time, causes the visible state of the second barcode, which is initially not readable, to become readable. Accordingly, the quality indicator of U.S. Ser. No. 12/469,309 presents a single readable barcode both before and after exceedance of a threshold.

The colorable common areas disclosed in U.S. Ser. No. 12/469,309 preferably include a single colorable area per barcode and preferably have the width of a single barcode bar. Accordingly, the difference between the readable state and the unreadable state of the barcodes disclosed in U.S. Ser. No. 12/469,309 is preferably a single barcode bar.

A problem may occur if a barcode is read by a barcode reader when the barcode is in an unreadable state. The more similar the unreadable state of a barcode is to the readable state thereof, the higher is the probability that the unreadable barcode will be erroneously read by a barcode reader. If a barcode reader erroneously reads either the first or the second barcode in the quality indicator of U.S. Ser. No. 12/469,309 when that barcode is in an unreadable state, the barcode reader may read a barcode presenting incorrect information. This problem can occur in situations such as described below, with reference to the embodiment disclosed on page 14, paragraph [0051] of U.S. Ser. No. 12/469,309:

In a first situation, the second barcode, which is not readable prior to exceedance of a threshold, is erroneously read by a barcode reader notwithstanding that the colorable common area has not yet become colored. At the same time, the first barcode remains readable because the first barcode becomes unreadable only upon coloring of the colorable common area. As a result, by reading the second unreadable barcode, the barcode reader reads a barcode presenting incorrect information.

In a second situation, the first barcode, which is readable prior to exceedance of a threshold, is erroneously still read by a barcode reader following exceedance of the threshold, notwithstanding that the colorable common area became colored and rendered the first barcode unreadable. At the same time, the second barcode becomes readable by virtue of the coloring of the colorable common area. As a result, by reading the first unreadable barcode, the barcode reader reads a barcode presenting incorrect information.

A group of colorable areas corresponding to the colorable common area disclosed in U.S. Ser. No. 12/469,309 and which are operative to become colored or uncolored at the same time, is hereinafter referred to as a common colorable region.

The common colorable region preferably has a width of a single narrow barcode bar. Alternatively, the common colorable region is wider than a single narrow barcode bar.

The present application provides an improvement to the quality indicator described in U.S. Ser. No. 12/469,309. This improvement alleviates the above problem by preferably including as part of a barcode at least one additional set of colorable areas, in addition to the common colorable region.

Each additional set of colorable areas, hereinafter referred to as an additional colorable region, preferably includes at least one colorable area, forms part of a single barcode and is configured to reduce the barcode readability level of the barcode of which it forms a part. Preferably, an additional colorable region includes more than one colorable area. Alternatively, an additional colorable region includes a single colorable area.

The phrase “barcode readability level” or “BCR level” of a barcode in an unreadable state reflects the likelihood that a barcode reader will erroneously read the barcode when it is in that unreadable state. Accordingly, an unreadable barcode having a low BCR level is not likely to be erroneously read by a barcode reader.

In accordance with a preferred embodiment of the present invention, in the first situation described above, the additional colorable region forms part of the initially unreadable second barcode, and includes an initially uncolored set of colorable areas. The initially uncolored set of colorable areas is preferably positioned at location of barcode bars which appear in the second barcode in its readable state. As a result, more than a single narrow barcode bar is missing from the second barcode. It is appreciated that as a result of more than a single narrow barcode bars being missing, the BCR level of the unreadable second barcode decreases and becomes lower than the BCR level of the unreadable second barcode in U.S. Ser. No. 12/469,309, wherein only a single barcode bar is missing.

Preferably, “more than a single narrow barcode bar” means more than one barcode bar, the barcode bars being narrow or wide. Alternatively, “more than a single narrow barcode bar means more than a portion of a wide barcode bar, the portion being at the same width as a narrow barcode bar.

It is appreciated that portions of barcode bars can be missing as a result of set of colorable areas not being colored.

In accordance with another preferred embodiment of the present invention, in the second situation described above, the additional colorable region forms part of the initially readable first barcode and includes an initially uncolored set of colorable areas. The initially uncolored set of colorable areas is preferably positioned in spaces between barcode bars which form part of the first barcode in its readable state, and when uncolored do not interfere with the readability of the first barcode.

Preferably, following exceedance of a threshold, colorable areas forming part of the common colorable region and of the additional colorable region become colored, thereby causing the first barcode to become unreadable. The coloring of the additional colorable region results in multiple spaces between bars of the first barcode becoming filled in, thereby decreasing the BCR level of the first barcode and causing it to be lower than that of the unreadable state of the first barcode described in U.S. Ser. No. 12/469,309, which has only a space having a width of a single barcode bar filled in relative to the readable state thereof.

It is appreciated that instead of multiple spaces becoming filled in between bars of the first barcode, a space which is wider than a single narrow barcode bar can become filled in.

According to the embodiment illustrated in FIGS. 3A-4K, the colorable areas forming part of the additional colorable region and the common colorable region become colored sequentially. Alternatively, the colorable areas forming part of the additional colorable region and of the common colorable region become colored generally simultaneously.

It is appreciated that a plurality of spaces between barcode bars which become filled in as a result of coloring of a set of colorable areas can include spaces which are partially filled in.

It is appreciated that instead of being initially uncolored and becoming colored, a colorable area can be initially colored and become uncolored.

Preferably, as colorable areas become colored, barcode bars or portions thereof appear and spaces between barcodes or portions thereof become filled in. Alternatively, as colorable areas become colored, barcode bars or portions thereof disappear and spaces or portions thereof form between barcode bars.

It is further appreciated that the quality indicator may be operative to provide an indication of exceedance only following actuation thereof. Alternatively, as illustrated in the description and drawings of this application, the quality indicator may be operative to provide an indication of exceedance without actuation.

According to a preferred embodiment of the present invention barcodes forming part of a quality indicator are each capable of indicating any numerical or alphanumerical sequence. Additionally or alternatively, barcodes forming part of a quality indicator are each capable of complying with any suitable barcode standard, including but not limited to EAN, UPC, 2 of 5 Interleaved, code39, code 39 extended, code 93, code 93 extended, code 128, code 128 A, B and C, ISBN, Code bar and Data Matrix. Accordingly, different barcodes forming part of the same quality indicator can comply with different barcode standards. For example, a quality indicator can include a first barcode complying with the EAN13 standard and a second barcode complying with the 2 of 5 Interleaved standard. Consequently, if the barcode reader of a checkout scanner is operative to read only the EAN13 barcode standard, then, once the first barcode becomes unreadable, the indicator no longer presents a readable barcode to the checkout scanner. However, the indicator is still readable by a barcode reader operative to read the 2 of 5 Interleaved standard.

Reference is now made to FIGS. 3A-3K, which together are a simplified illustration of the construction and operation of one embodiment of a quality indicator for indicating a combination of elapsed time and temperature. The quality indicator described in FIGS. 3A-3K is operative to provide separate indications of exceedance of two different time durations, one hour, and three and a half hours, at a temperature of at least 21 degrees Celsius.

In each of FIGS. 3A-3K, the quality indicator 300 appears both in an exploded view at the top left portion of the drawing and in a planar view at the bottom right portion of the drawing.

As seen in the exploded view in FIGS. 3A-3K, the quality indicator, here indicated by reference number 300, preferably includes a barcode defining layer 302, which is preferably printed on a transparent substrate. The printing on the transparent substrate preferably defines a background area 303, which is preferably printed with black ink and overprinted with white ink, a plurality of bars 304 forming part of barcodes I, II and III which are preferably printed with black ink, and a plurality of transparent areas 305, which are preferably printed with light blue ink, such as Pantone No. 645, which has a visual appearance similar to that of the black ink overprinted with white ink. Alternatively, the background area 303 and the plurality of bars 304 are printed in such colors so as to define high contrast therebetween.

For the purposes of the present specification and claims, the phrase “transparent areas” is defined so as to include within its scope areas that are either transparent or translucent.

The barcodes I, II and III are preferably arranged in a stacked arrangement and the transparent areas 305 preferably form part of six regions: a common colorable region 310 forming part of barcodes I and II, an additional colorable region 311 forming part of barcode I, an additional colorable region 312 forming part of barcode II, a common colorable region 313 forming part of barcodes II and III, an additional colorable region 314 forming part of barcode II and an additional colorable region 315 forming part of barcode III.

It is appreciated that barcodes I, II and III need not be positioned on the indicator in any particular order.

It is also appreciated that the spaces which appear in FIGS. 3A-3K between barcode I and barcode II and between barcode II and barcode III may be obviated.

Preferably, the common colorable region 310 includes two transparent areas, transparent area 316 forming part of barcode I and transparent area 317 forming part of barcode II.

Preferably, the common colorable region 313 includes two transparent areas, transparent area 318 forming part of barcode II and transparent area 319 forming part of barcode III.

According to the embodiment illustrated in FIGS. 3A-3K, the additional colorable region 311, forming part of barcode I, appears to the right of the transparent area 316. The transparent area 316 and the transparent areas 305 which form part of the additional colorable region 311 are preferably positioned in spaces between barcode bars forming part of barcode I in its readable state, which is indicated by reference numeral 340 in FIG. 3A.

For the purpose of the explanation which follows, the transparent areas 305 forming part of the additional colorable region 311 are grouped into two pluralities of transparent areas: 321 and 322, as illustrated in FIGS. 3A-3K.

According to the embodiment illustrated in FIGS. 3A-3K, the additional colorable region 312 forming part of barcode II appears to the left of the transparent area 317. The transparent area 317 and the transparent areas 305 which from part of the additional colorable region 312 are positioned at locations of bars which appear when barcode II is in its readable state, which is indicated by reference numeral 363 in FIG. 3E.

For the purpose of the explanation which follows, the transparent areas 305 forming part of the additional colorable region 312 are grouped into two pluralities of transparent areas: 324 and 325, as illustrated in FIGS. 3A-3K.

According to the embodiment illustrated in FIGS. 3A-3K, the additional colorable region 314, forming part of barcode II, appears to the right of the transparent area 318. The transparent area 318 and the transparent areas 305 which form part of the additional colorable region 314 are preferably positioned in the spaces between barcode bars forming part of barcode II in its readable state, which is indicated by reference numeral 363 in FIG. 3E.

According to the embodiment illustrated in FIGS. 3A-3K, the additional colorable region 315 forming part of barcode III appears to the left of the transparent area 319. The transparent area 319 and the transparent areas 305 which form part of the additional colorable region 315 are positioned at locations of bars which appear when barcode III is in its readable state, which is indicated by reference numeral 375 in FIG. 3J.

Disposed behind the barcode defining layer 302 and preferably adhered thereto is a colorable element 330, such as Whatman No. 3 filter paper commercially available from Whatman International [CAT #: 1003917], which until colored is normally white. The colorable element 330 preferably extends behind the common colorable regions 310 and 313 and the additional colorable regions 311, 312, 314 and 315.

Disposed behind the barcode defining layer 302 and behind the colorable element 330 is a back layer 335. Preferably adhered to the back layer 335 rearwardly of the colorable element 330 is a temperature responsive coloring element 336, such as a pad, for example, K-R; 210/34/28, commercially available from Noam-Urim of Kibbutz Urim, Israel, impregnated with a coloring agent, such as Sudan Black, a black color dye [CAS: 4197-25-5], dissolved at a ratio of 1 gram per 1 kg in Coconut oil [CAS: 8001-31-8].

Turning now to FIG. 3A, as can be seen in the planar view, barcode I is initially in a readable state indicated by reference numeral 340, which is typically readable by a barcode reader as 7290003804115 and barcodes II and III are in unreadable states indicated by reference numerals 341 and 342, respectively.

As can be seen in the exploded view of FIG. 3A, the transparent area 317 and the transparent areas 305 forming part of the additional colorable region 312 forming part of barcode II are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode II in its readable state are missing from barcode II. The missing plurality of barcode bars results in barcode II in the initial unreadable state 341 having a BCR level lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309, in which only a single narrow barcode bar is missing.

As can also be seen in the exploded view of FIG. 3A, the transparent area 319 and the additional colorable region 315 forming part of barcode II are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode II in its readable state are missing from barcode III. The missing plurality of barcode bars results in barcode III in the initial unreadable state 342 having a BCR level lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309, in which only a single narrow barcode bar is missing.

As a result, a barcode reader is less likely to read the unreadable barcodes II or III in their current state than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

Turning to FIG. 3B, as can be seen in the exploded view, when the temperature at the quality indicator exceeds 21 degrees Celsius, such as when the temperature reaches 25 degrees Celsius, the coloring agent, indicated by reference number 350 begins to melt and be released from the coloring element 336 and begins to diffuse through the colorable element 330. The colored portions of the colorable element 330 cannot be seen through the plurality of the transparent areas 305 and, as can be seen in the planar view, barcodes I, II and III remain unchanged.

Turning to FIG. 3C, as can be seen in the exploded view, following the elapse of a certain amount of time at 25 degrees, for example 30 minutes, the coloring agent 350 continues to diffuse through the colorable element 330. As a result, portions of the colorable element 330 are visible through the plurality of transparent areas indicated by reference number 324, resulting in the appearance of a plurality of bars indicated by reference numeral 352 forming part of barcode U, as can be seen in the planar view. Barcode I remains in the readable state 340, barcode III remains in the unreadable state 342, and the changed unreadable state of barcode II is indicated by reference number 353.

The barcode bars which appear at the locations of the transparent area 317 and of the plurality of transparent areas 325 when barcode II in its readable state, indicated by reference numeral 363 in FIG. 3E, are still missing from barcode II. This missing plurality of barcode bars results in the BCR level of barcode II in the unreadable state 353 being still lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is still less likely to read the unreadable barcodes II or III in their current state than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 3B and 3C, less barcode bars are missing when barcode II is in the unreadable state 353 than when it is in the unreadable state 341. Accordingly, it is appreciated that the BCR level of barcode II in the unreadable state 353 is higher than the BCR level thereof in the unreadable state 341.

Turning to FIG. 3D, as can be seen in the exploded view, following the elapse of an additional amount of time at 25 degrees, for example another 25 minutes, the coloring agent 350 continues to diffuse through the colorable element 330. As a result, portions of the colorable element 330 are visible through the plurality of transparent areas indicated by reference number 325, resulting in the appearance of an additional plurality of bars 354 forming part of barcode I, as can be seen in the planar view. Barcode I remains in the readable state 340, barcode III remains in the unreadable state 342 and the changed unreadable state of barcode II is indicated by reference number 355. Only a single narrow barcode bar which appears at the location of the transparent area 317 when barcode II in its readable state, indicated by reference numeral 363 in FIG. 3E, is still missing from barcode II, and the missing barcode bar renders barcode II in state 355 unreadable.

It is appreciated that because only a single narrow barcode bar is missing in the unreadable state 355, the BCR level of barcode II in the unreadable state 355 is higher than that of barcode II in the unreadable states 341 and 353 described in FIGS. 3A-3C above. It is further appreciated that barcode II in the unreadable state 355 has a BCR level similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309.

Turning to FIG. 3E, as can be seen in the exploded view, when a threshold is exceeded by the temperature at the indicator being at least 21 degrees Celsius for at least a predetermined cumulative amount of time, such as 25 degrees Celsius for a total of at least one hour, the coloring agent 350 diffuses through the colorable element 330, such that portions of the colorable element 330 are visible through the common colorable region 310, including the transparent areas indicated by reference numerals 316 and 317.

As a result of portions of the colorable element 330 being visible through the transparent area indicated by reference numeral 316, a space indicated by reference numeral 360, which is located between bars of barcode I in its readable state, is filled in, thereby causing barcode I to assume an unreadable state 361, as can be seen in the planar view.

As a result of portions of the colorable element 330 being visible through the transparent area indicated by reference numeral 317, a single narrow barcode bar indicated by reference numeral 362 appears in barcode II, thereby causing barcode II to assume a readable state 363, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804139.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode I in its readable state is filled in, the BCR level of barcode I in the unreadable state 361 is high, similar to the BCR level of barcode II in the unreadable state 355 described in FIG. 3D above. It is further appreciated that the BCR level of barcode I in the unreadable state 361 is similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes I, II and III in FIG. 4E of U.S. Ser. No. 12/469,309.

Turning to FIG. 3F, as can be seen in the exploded view, if the temperature is at least 21 degrees Celsius for an additional amount of time, for example 25 degrees Celsius for an additional 30 minutes, the coloring agent 350 continues to diffuse through the colorable element 330, such that portions of the colorable element 330 are visible through the transparent areas indicated by reference numeral 321. As a result, a plurality of spaces indicated by reference numeral 365 located between the bars of barcode I in its readable state is filled in, as can be seen in the planar view. Barcode II remains in the readable state 363, barcode III remains in the unreadable state 342 and barcode I assumes a further unreadable state, indicated by reference number 366. As a result of the coloring of the plurality of spaces 365, the BCR level of barcode I in the unreadable state 366 decreases and becomes lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes I or III in their current state than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 3E and 3F, more spaces are filled in between bars of barcode I in the unreadable state 366 than in the unreadable state 361. Accordingly, it is appreciated that the BCR level of barcode I is lower in the unreadable state 366 than in the unreadable state 361.

Turning to FIG. 3G, as can be seen in the exploded view, if the temperature is at least 21 degrees Celsius for an additional amount of time, for example 25 degrees Celsius for an additional 30 minutes, the coloring agent 350 continues to diffuse through the colorable element 330, such that portions of the colorable element 330 are visible through the transparent areas indicated by reference number 322. As a result, an additional plurality of spaces indicated by reference numeral 367, located between the bars of barcode I in its readable state, appears colored, as can be seen in the planar view. Barcode II remains in the readable state 363, barcode III remains in the unreadable state 342 and barcode I assumes a further unreadable state 368. As a result of the coloring of the additional plurality of spaces 367, the BCR level of barcode I in the unreadable state 368 further decreases and continues to be lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes I or III in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 3F and 3G, more spaces are filled in between barcode bars of barcode I in the unreadable state 368 than in the unreadable state 366. Accordingly, the BCR level of barcode I is lower in the unreadable state 368 than in the unreadable state 366.

Turning to FIG. 3H, as can be seen in the exploded view, if the temperature is at least 21 degrees Celsius for an additional amount of time, for example 25 degrees Celsius for an additional one hour, the coloring agent 350 continues to diffuse through the colorable element 330. The additional colored portions of the colorable element 330 are not seen through the plurality of the transparent areas 305 and, as can be seen in the planar view, barcodes I, II and III remain unchanged.

As can be seen in the exploded view of FIG. 3H, the transparent area 319 and the additional colorable region 315 forming part of barcode III are still uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode III in its readable state, indicated by reference numeral 375 in FIG. 33 , are still missing from barcode III. The missing barcode bars result in barcode III in the unreadable state 342 having a BCR level lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309, in which only a single narrow barcode bar is missing.

As a result, a barcode reader is less likely to read the unreadable barcodes I or III in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

Turning to FIG. 3I, as can be seen in the exploded view, following the elapse of an additional amount of time at 25 degrees, for example another 25 minutes, the coloring agent 350 continues to diffuse through the colorable element 330. As a result, portions of the colorable element 330 are visible through the plurality of transparent areas 305 forming part of the additional colorable region indicated by reference number 315, resulting in the appearance of a plurality of bars 370 forming part of barcode II, as can be seen in the planar view. Barcode I remains in the unreadable state 368, barcode II remains in the readable state 363 and the changed unreadable state of barcode III is indicated by reference number 371. Only a portion of a barcode bar which appears at the location of the transparent area 319 when barcode III in its readable state, the portion having a width of a single narrow barcode bar, is still missing from barcode III, and the missing barcode bar portion renders barcode III in state 371 unreadable.

It is appreciated that because only a portion of a barcode bar is missing in the unreadable state 371, the portion having a width of a single narrow barcode bar, the BCR level of barcode III in the unreadable state 371 is higher than that of barcode III in the unreadable state 342 described in FIG. 3A-3H above. It is further appreciated that barcode III in the unreadable state 371 has a high BCR level, which is similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309.

Turning to FIG. 33 , as can be seen in the exploded view, when a second threshold is exceeded by the temperature at the indicator being at least 21 degrees Celsius for at least a second predetermined cumulative amount of time, such as 25 degrees Celsius for a total of at least three and a half hours, the coloring agent 350 diffuses through the colorable element 330, such that portions of the colorable element 330 are visible through the common colorable region 313, including the transparent areas indicated by reference numerals 318 and 319.

As a result of portions of the colorable element 330 being visible through the transparent area indicated by reference numeral 318, a space indicated by reference numeral 372, which is located between bars of barcode II in its readable state, is filled in, thereby causing barcode II to assume an unreadable state 373, as can be seen in the planar view.

As a result of portions of the colorable element 330 being visible through the transparent area indicated by reference numeral 319, a portion of a barcode appears in barcode III, the portion being indicated by reference numeral 374 and having a width of a single narrow barcode bar. As a result, barcode III assumes a readable state 375, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804122.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode II in its readable state is filled in, the BCR level of barcode II in the unreadable state 373 is high, similar to the BCR level of barcode II in the unreadable state 371 described in FIG. 3I above. It is further appreciated that the BCR level of barcode II in the unreadable state 373 is similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes I, II and III in FIG. 4E of U.S. Ser. No. 12/469,309.

Turning to FIG. 3K, as can be seen in the exploded view, if the temperature is at least 21 degrees Celsius for an additional amount of time, for example 25 degrees Celsius for an additional 30 minutes, the coloring agent 350 continues to diffuse through the colorable element 330, such that portions of the colorable element 330 are visible through the transparent areas 305 forming part of the additional colorable region indicated by reference number 314. As a result, a plurality of spaces 376, located between the bars of barcode II in its readable state, is filled in, as can be seen in the planar view. Barcode I remains in the unreadable state 368, barcode III remains in the readable state 375 and barcode II assumes a further unreadable state, indicated by reference numeral 377. The plurality of spaces 376 becoming filled in causes the BCR level of barcode II in the unreadable state 377 to decrease and be lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes I or II in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 3M and 3K, more spaces are filled in between barcode bars of barcode II in the unreadable state 377 than in the unreadable state 373. Accordingly, it is appreciated that the BCR level of barcode II is lower in the unreadable state 377 than in the unreadable state 373.

It is appreciated that if the temperature drops below 21 degrees Celsius the coloring agent 350 continues to diffuse through the colorable element 330. If, after the temperature reaches 21 degrees Celsius, the temperature drops below 17 degrees Celsius, then the coloring agent 350 becomes solid and diffusion thereof through the colorable element 330 is suspended until the temperature again reaches 21 degrees Celsius.

Reference is now made to FIGS. 4A-4K, which together are a simplified illustration of the construction and operation of one embodiment of a quality indicator for indicating a combination of elapsed time and temperature. The quality indicator described in FIGS. 4A-4K is operative to provide separate indications of exceedance of two different temperatures: 12 degrees Celsius and 21 degrees Celsius, for a time duration of at least one hour at each temperature.

In each of FIGS. 4A-4K, the quality indicator 400 appears both in an exploded view at the top left portion of the drawing and in a planar view at the bottom right portion of the drawing.

As seen in the exploded view in FIGS. 4A-4K, the quality indicator, here indicated by reference number 400, preferably includes a barcode defining layer 402, which is preferably printed on a transparent substrate. The printing on the transparent substrate preferably defines a background area 403, which is preferably printed with black ink and overprinted with white ink, a plurality of bars 404 forming part of barcodes IV, V and VI which are preferably printed with black ink, and a plurality of transparent areas 405, which are preferably printed with light blue ink, such as Pantone No. 645, which has a visual appearance similar to that of the black ink overprinted with white ink. Alternatively, the background area 403 and the plurality of ban 404 are printed in such colors so as to define high contrast therebetween.

The barcodes IV, V and VI are preferably arranged in a stacked arrangement and the transparent areas 405 preferably form part of six regions: a common colorable region 410 forming part of barcodes IV and V, an additional colorable region 411 forming part of barcode IV, an additional colorable region 412 forming part of barcode V, a common colorable region 413 forming part of barcodes V and VI, an additional colorable region 414 forming part of barcode V and an additional colorable region 415 forming part of barcode VI.

It is appreciated that barcodes IV, V and VI need not be positioned on the indicator in any particular order.

It is also appreciated that the spaces which appear FIGS. 4A-4K between barcode IV and barcode V and between barcode V and barcode VI may be obviated.

Preferably, the common colorable region 410 includes two transparent areas, transparent area 416 forming part of barcode IV and transparent area 417 forming part of barcode V.

Preferably, the common colorable region 413 includes two transparent areas, transparent area 418 forming part of barcode V and transparent area 419 forming part of barcode VI.

According to the embodiment illustrated in FIGS. 4A-4K, the additional colorable region 411, forming part of barcode IV, appears to the right of the transparent area 416. The transparent area 416 and the transparent areas 405 which form part of the additional colorable region 411 are preferably positioned in the spaces between barcode bars forming part of barcode IV in its readable state, which is indicated by reference numeral 440 in FIG. 4A.

For the purpose of the explanation which follows, the transparent areas 405 forming part of the additional colorable region 411 are grouped into two pluralities of transparent areas: 421 and 422, as illustrated in FIGS. 4A-4K.

According to the embodiment illustrated in FIGS. 4A-4K, the additional colorable region 412 forming part of barcode V appears to the left of the transparent area 417. The transparent area 417 and the transparent areas 405 which form part of the additional colorable region 412 are positioned at locations of bars which appear when barcode V is in its readable state, which is indicated by reference numeral 463 in FIG. 4E.

For the purpose of the explanation which follows, the transparent areas 405 forming part of the additional colorable region 412 are grouped into two pluralities of transparent areas: 424 and 425, as illustrated in FIGS. 4A-4K.

According to the embodiment illustrated in FIGS. 4A-4K, the additional colorable region 414, forming part of barcode V, appears to the left of the transparent area 418. The transparent area 418 and the transparent areas 405 which form part of the additional colorable region 414 are preferably positioned in the spaces between barcode bars forming part of barcode V in its readable state, which is indicated by reference numeral 463 in FIG. 4E.

According to the embodiment illustrated in FIGS. 4A-4K, the additional colorable region 415 forming part of barcode VI appears to the right of the transparent area 419. The transparent area 419 and the transparent areas 405 which form part of the additional colorable region 415 are positioned at locations of bars which appear when barcode VI is in its readable state, which is indicated by reference numeral 475 in FIG. 4J.

Disposed behind the barcode defining layer 402 and preferably adhered thereto is a colorable element 430, such as Whatman No. 3 filter paper commercially available from Whatman International [CAT #: 1003917], which until colored is normally white. The colorable element 430 preferably extends behind the common colorable region 410 and the additional colorable regions 411 and 412.

Also disposed behind the barcode defining layer 402 and preferably adhered thereto is an additional colorable element 432, such as Whatman No. 3 filter paper commercially available from Whatman International [CAT #: 1003917], which until colored is normally white. The colorable element 432 is preferably adjacent the colorable element 430 and preferably extends behind the common colorable region 413 and the additional colorable regions 414 and 415.

It is appreciated that instead of including two separate colorable elements, an indicator according to the present invention can include a single colorable element separated into two portions by a separator made of a material which is impermeable to ink, such as varnish.

Disposed behind the barcode defining layer 402 and behind the colorable elements 430 and 432 is a back layer 435.

Preferably adhered to the back layer 435 rearwardly of the colorable element 430 is a temperature responsive coloring element 436, such as a pad, for example, K-R; 210/34/28, commercially available from Noam-Urim of Kibbutz Urim, Israel, impregnated with a coloring agent, such as Sudan Black, a black color dye [CAS: 4197-25-5], dissolved at a ratio of 1 grain per 1 kg in a solution of 74.25% Coconut oil [CAS: 8001-31-8], 24.75% Oleic acid [CAS: 112-80-1] and 1% Hexanoic acid [CAS: 142-62-1].

Preferably also adhered to the back layer 435 rearwardly of the colorable element 432 is a temperature responsive coloring element 438, such as a pad, for example, K-R; 210/34/28, commercially available from Noam-Urim of Kibbutz Urim, Israel, impregnated with a coloring agent, such as Sudan Black, a black color dye [CAS: 4197-25-5], dissolved at a ratio of 1 gram per 1 kg in Coconut oil [CAS: 8001-31-8].

Turning now to FIG. 4A, as can be seen in the planar view, barcode IV is initially in a readable state indicated by reference numeral 440, which is typically readable by a barcode reader as 7290003804115 and barcodes V and VI are in unreadable states indicated by reference numerals 441 and 442, respectively.

As can be seen in the exploded view of FIG. 4A, the transparent area 417 and the transparent areas 405 forming part of the additional colorable region 412 forming part of barcode V are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode V in its readable state are missing from barcode V. The missing plurality of barcode bars results in barcode V in the initial unreadable state 441 having a BCR level lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309, in which only a single barcode bar is missing.

As can also be seen in the exploded view of FIG. 4A, the transparent area 419 and the additional colorable region 415 forming part of barcode VI are initially uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode VI in its readable state are missing from barcode VI. The missing plurality of barcode bars results in barcode VI in the initial unreadable state 442 having a BCR level lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309, in which only a single narrow barcode bar is missing.

As a result, a barcode reader is less likely to read the unreadable barcodes V or VI in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

Turning to FIG. 4B, as can be seen in the exploded view, when the temperature at the quality indicator exceeds 12 degrees Celsius, such as when the temperature reaches 15 degrees Celsius, the coloring agent, indicated by reference numeral 450 begins to melt and be released from the coloring element 436 and begins to diffuse through the colorable element 430. The colored portions of the colorable element 430 cannot be seen through the plurality of the transparent areas 405 and, as can be seen in the planar view, barcodes IV, V and VI remain unchanged.

Turning to FIG. 4C, as can be seen in the exploded view, following the elapse of a certain amount of time at 15 degrees, for example 30 minutes, the coloring agent 450 continues to diffuse through the colorable element 430. As a result, portions of the colorable element 430 are visible through the plurality of transparent areas indicated by reference numeral 424, resulting in the appearance of a plurality of bars indicated by reference numeral 452 forming part of barcode V, as can be seen in the planar view. Barcode IV remains in the readable state 440, barcode VI remains in the unreadable state 442, and the changed unreadable state of barcode V is indicated by reference number 453.

The barcode bars which appear at the locations of the transparent area 417 and of the plurality of transparent areas 425 when barcode V in its readable state, indicated by reference numeral 463 in FIG. 4E, are still missing from barcode V. This missing plurality of barcode bars results in the BCR level of barcode II in the unreadable state 453 being still lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes V or VI in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 4B and 4C, less barcode bars are missing when barcode V is in the unreadable state 453 than when it is in the unreadable state 441. Accordingly, it is appreciated that the BCR level of barcode V in the unreadable state 453 is higher than the BCR level thereof in the unreadable state 441.

Turning to FIG. 4D, as can be seen in the exploded view, following the elapse of an additional amount of time at 15 degrees, for example another 25 minutes, the coloring agent 450 continues to diffuse through the colorable element 430. As a result, portions of the colorable element 430 are visible through the plurality of transparent areas indicated by reference numeral 425, resulting in the appearance of an additional plurality of bars 454 forming part of barcode V, as can be seen in the planar view. Barcode IV remains in the readable state 440, barcode VI remains in the unreadable state 442 and the changed unreadable state of barcode V is indicated by reference number 455. Only a single narrow barcode bar which appears at the location of the transparent area 417 when barcode V in its readable state, indicated by reference numeral 463 in FIG. 4E, is still missing from barcode V. and the missing barcode bar renders barcode V in state 455 unreadable.

It is appreciated that because only a single barcode bar is missing in the unreadable state 455, the BCR level of barcode V in the unreadable state 455 is higher than that of barcode V in the unreadable states 441 and 453 described in FIGS. 4A-4C above. It is further appreciated that barcode V in the unreadable state 455 has a BCR level similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309.

Turning to FIG. 4E, as can be seen in the exploded view, when a threshold is exceeded by the temperature at the indicator being at least 12 degrees Celsius for at least a predetermined cumulative amount of time, such as 15 degrees Celsius for a total of at least one hour, the coloring agent 450 diffuses through the colorable element 430, such that portions of the colorable element 430 are visible through the common colorable region 410, including the transparent areas indicated by reference numerals 416 and 417.

As a result of portions of the colorable element 430 being visible through the transparent area indicated by reference numeral 416, a space indicated by reference numeral 460, which is located between bars of barcode IV in its readable state, is filled in, thereby causing barcode IV to assume an unreadable state 461, as can be seen in the planar view.

As a result of portions of the colorable element 430 being visible through the transparent area indicated by reference numeral 417, a single barcode bar indicated by reference numeral 462 appears in barcode V, thereby causing barcode V to assume a readable state 463, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804139.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode IV in its readable state is filled in, the BCR level of barcode IV in the unreadable state 461 is high, similar to the BCR level of barcode V in the unreadable state 455 described in FIG. 4D above. It is further appreciated that the BCR level of barcode IV in the unreadable state 461 is similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes I, II and III in FIG. 4E of U.S. Ser. No. 12/469,309.

Turning to FIG. 4F, as can be seen in the exploded view, if the temperature is at least 12 degrees Celsius for an additional amount of time, for example 15 degrees Celsius for an additional 30 minutes, the coloring agent 450 continues to diffuse through the colorable element 430, such that portions of the colorable element 430 are visible through the transparent areas indicated by reference numeral 421. As a result, a plurality of spaces indicated by reference numeral 465 located between the bars of barcode IV in its readable state are filled in, as can be seen in the planar view. Barcode V remains in the readable state 463, barcode VI remains in the unreadable state 442 and barcode IV assumes a further unreadable state, indicated by reference number 466. As a result of the plurality of spaces 465 becoming filled in, the BCR level of barcode IV in the unreadable state 466 decreases and becomes lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes IV or VI in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 4E and 4F, more spaces are filled in between barcode bars of barcode IV in the unreadable state 466 than in the unreadable state 461. Accordingly, it is appreciated that the BCR level of barcode IV is lower in the unreadable state 466 than in the unreadable state 461.

Turning to FIG. 4G, as can be seen in the exploded view, if the temperature is at least 12 degrees Celsius for an additional amount of time, for example 15 degrees Celsius for an additional 30 minutes, the coloring agent 450 continues to diffuse through the colorable element 430, such that portions of the colorable element 430 are visible through the transparent areas indicated by reference number 422. As a result, an additional plurality of spaces indicated by reference numeral 467, located between the bars of barcode IV in its readable state, are filled in, as can be seen in the planar view. Barcode V remains in the readable state 463, barcode VI remains in the unreadable state 442 and barcode IV assumes a further unreadable state 468. As a result of the additional plurality of spaces 467 becoming filled in, the BCR level of barcode IV in the unreadable state 468 further decreases and continues to be lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes IV or VI in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 4F and 40 , more spaces are filled in between barcode bars of barcode IV in the unreadable state 468 than in the unreadable state 466. Accordingly, the BCR level of barcode IV is lower in the unreadable state 468 than in the unreadable state 466.

It is appreciated that if the temperature drops below 12 degrees Celsius, the coloring agent 450 continues to diffuse through the colorable element 430. If, at any time after the temperature reaches 12 degrees Celsius, the temperature drops below 7 degrees Celsius, then the coloring agent 450 becomes solid and diffusion thereof through the colorable element 430 is suspended until the temperature again reaches 12 degrees Celsius.

Turning to FIG. 411 , as can be seen in the exploded view, when the temperature at the quality indicator exceeds 21 degrees Celsius, such as when the temperature reaches 25 degrees Celsius, the coloring agent, indicated by reference number 469 begins to melt and be released from the coloring element 438 and begins to diffuse through the colorable element 432. The colored portions of the colorable element 432 cannot be seen through the plurality of the transparent areas 405 and, as can be seen in the planar view, barcodes IV, V and VI remain unchanged.

As can be seen in the exploded view of FIG. 4H, the transparent area 419 and the additional colorable region 415 forming part of barcode VI are still uncolored. As a result, as can be seen in the planar view, a plurality of bars which appear when barcode VI in its readable state, indicated by reference numeral 475 in FIG. 4J, are still missing from barcode VI. The missing barcode bars result in barcode VI in the unreadable state 442 having a BCR level lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309, in which only a single narrow barcode bar is missing.

As a result, a barcode reader is less likely to read the unreadable barcodes IV or VI in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

Turning to FIG. 4I, as can be seen in the exploded view, following the elapse of a certain amount of time at 25 degrees, for example 55 minutes, the coloring agent 469 continues to diffuse through the colorable element 432. As a result, portions of the colorable element 432 are visible through the plurality of transparent areas 405 forming part of the additional colorable region indicated by reference number 415, resulting in the appearance of a plurality of bars 470 forming part of barcode VI, as can be seen in the planar view. Barcode IV remains in the unreadable state 468, barcode V remains in the readable state 463 and the changed unreadable state of barcode VI is indicated by reference number 471. Only a single narrow barcode bar, which appears at the location of the transparent area 419 when barcode VI in its readable state, is still missing from barcode VI, and the missing barcode bar renders barcode VI in state 471 unreadable.

It is appreciated that because only a single narrow barcode bar is missing in the unreadable state 471, the BCR level of barcode VI in the unreadable state 471 is higher than that of barcode VI in the unreadable state 442 described in FIG. 4A-4H above. It is further appreciated that barcode VI in the unreadable state 471 has a high BCR level, which is similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes II, III and IV in FIG. 4A of U.S. Ser. No. 12/469,309.

Turning to FIG. 4J, as can be seen in the exploded view, when a second threshold is exceeded by the temperature at the indicator being at least 21 degrees Celsius for at least a predetermined cumulative amount of time, such as 25 degrees Celsius for a total of at least one hour, the coloring agent 469 diffuses through the colorable element 432, such that portions of the colorable element 432 are visible through the common colorable region 413, including the transparent areas indicated by reference numerals 418 and 419.

As a result of portions of the colorable element 432 being visible through the transparent area indicated by reference numeral 418, a space indicated by reference numeral 472, which is located between bars of barcode V in its readable state, is filled in thereby causing barcode V to assume an unreadable state 473, as can be seen in the planar view.

As a result of portions of the colorable element 432 being visible through the transparent area indicated by reference numeral 419, a single narrow barcode bar indicated by reference numeral 474 appears in barcode VI, thereby causing barcode VI to assume a readable state 475, as can be seen in the planar view, which is typically readable by a barcode reader as 7290003804122.

It is appreciated that because a space preferably having a width of a single narrow barcode bar located between the bars of barcode V in its readable state is filled in, the BCR level of barcode V in the unreadable state 473 is high, similar to the BCR level of barcode VI in the unreadable state 471 described in FIG. 4I above. It is further appreciated that the BCR level of barcode V in the unreadable state 473 is similar to the BCR level of the unreadable barcodes described in U.S. Ser. No. 12/469,309, for example barcodes I, II and III in FIG. 4E of U.S. Ser. No. 12/469,309.

It is appreciated that since the distance between the common colorable region 413 and the coloring element 438 is at least equal to the distance between the common colorable region 410 and the coloring element 436, the common colorable region 413 will not become colored prior to the coloring of the common colorable region 410. Alternatively, the colorable elements 430 and 432 are made from different materials such that diffusion along the colorable element 432 is slower than diffusion along the colorable element 430.

According to an embodiment of the present invention, if the second threshold may be exceeded before the first threshold is exceeded, for example, by the second threshold including a temperature higher than that of the first threshold and a time duration shorter than that of the first threshold, an additional colorable area is added in barcode IV such that both barcodes IV and V become unreadable in response to exceedance of the second threshold. In accordance with this embodiment, if the first threshold is exceeded only following exceedance of the second threshold, exceedance of the first threshold will not be indicated.

In accordance with another embodiment of the present invention, the colorable element is not separated into two portions, and indication of exceedance of the second threshold can also result from exceedance of a second time duration at or above the predetermined temperature of the first threshold.

Turning to FIG. 4K, as can be seen in the exploded view, if the temperature is at least 21 degrees Celsius for an additional amount of time, for example 25 degrees Celsius for an additional 30 minutes, the coloring agent 469 continues to diffuse through the colorable element 432, such that portions of the colorable element 432 are visible through the transparent areas 405 forming part of the additional colorable region indicated by reference number 414. As a result, a plurality of spaces 476, located between the bars of barcode V in its readable state, is filled in, as can be seen in the planar view. Barcode IV remains in the unreadable state 468, barcode VI remains in the readable state 475 and barcode V assumes a further unreadable state, indicated by reference numeral 477. As a result of the plurality of spaces 476 becoming filled in, the BCR level of barcode V in the unreadable state 477 decreases and becomes lower than that of the unreadable barcodes disclosed in U.S. Ser. No. 12/469,309.

As a result, a barcode reader is less likely to read the unreadable barcodes IV or V in their current unreadable states than read the unreadable barcodes of U.S. Ser. No. 12/469,309.

As can be seen from the planar view of FIGS. 4Q and 4K, more spaces are filled in between barcode bars of barcode V in the unreadable state 477 than in the unreadable state 473. Accordingly, it is appreciated that the BCR level of barcode V is lower in the unreadable state 477 than in the unreadable state 473.

It is appreciated that if the temperature drops below 21 degrees Celsius the coloring agent 469 continues to diffuse through the colorable element 432. If, after the temperature reaches 21 degrees Celsius, the temperature drops below 17 degrees Celsius, then the coloring agent 469 becomes solid and diffusion thereof through the colorable element 432 is suspended until the temperature again reaches 21 degrees Celsius.

In the embodiment described in FIGS. 4A-4K above, the coloring agent 469 moves along the coloring element 432 from right to left and therefore the additional colorable region 414, forming part of barcode V, appears to the left of the transparent area 418 and the additional colorable region 415, forming part of barcode VI, appears to the right of the transparent area 419. Alternatively, the coloring agent 469 can move along the coloring element 432 from left to right, and then the additional colorable region 414 would appear to the right of the transparent area 418 and the additional colorable region 415 would appear to the left of the transparent area 419, as illustrated in FIGS. 3A-3K.

It is appreciated that if the temperature increases above a second predetermined temperature before exceedance of a first threshold, which includes a first predetermined time duration at a first predetermined temperature, the coloring agent responsive to the second predetermined temperature melts and starts to be released from the corresponding coloring element before coloring of the common colorable region which is operative to indicate the exceedance of the first threshold. For example, in the embodiment illustrated in FIGS. 4A-4K above, if the temperature exceeds 21 degrees Celsius before the exceedance of one hour at a temperature of at least 12 degrees Celsius, the coloring agent 469 melts and starts to be released from the coloring element 432, before coloring of the common colorable region 410.

It is appreciated that an indicator according to the present invention can include more than three barcodes, wherein only one barcode is readable generally at any given time and as a result of exceedance of a threshold the readable barcode becomes unreadable and one of the unreadable barcodes becomes readable.

It is appreciated that the background of the barcode defining layer of the indicator may be printed in a dark color and the bars of the barcode may be printed in a light color.

It is appreciated that the melting of the coloring agent may be caused by a change in ambient parameters other than temperature, such as pH1, humidity or the presence of certain chemicals, thereby enabling the use of the indicators described in the present invention for indicating exceedance of thresholds relating to such parameters.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and sub-combinations of various features of the invention and modifications thereof which may occur to persons skilled in the art upon reading the foregoing description and which are not in the prior art. 

1-20. (canceled)
 21. A variable barcoded indicator comprising: at least one barcode, said at least one barcode including at least one machine readable state, a first non-machine-readable state and a second non-machine-readable state, said at least one barcode having a lower likelihood that a barcode reader will erroneously read the barcode when it is in said first non-machine-readable state than when it is in said second non-machine-readable state.
 22. A variable barcoded quality indicator according to claim 21, wherein said at least one barcode includes at least one colorable area.
 23. A variable barcoded quality indicator according to claim 22, further comprising: a coloring agent located at a first location on said indicator; and a coloring agent pathway operative to allow said coloring agent to move from said first location to said at least one colorable area for coloring thereof.
 24. A variable barcoded quality indicator according to claim 23 and wherein coloring of said at least one colorable area by said coloring agent is operative to change said at least one barcode from said first non-machine readable state to said second non-machine readable state.
 25. A variable barcoded quality indicator according to claim 23 and wherein coloring of said at least one colorable area by said coloring agent is operative to change said at least one barcode from said second non-machine readable state to said first non-machine readable state.
 26. A variable barcoded quality indicator according to claim 23 and wherein coloring of said at least one colorable area by said coloring agent is operative to change said at least one barcode from said machine readable state to one of said first non-machine-readable state and said second non-machine readable state.
 27. A variable barcoded quality indicator according to claim 23 and wherein coloring of said at least one colorable area by said coloring agent is operative to change said at least one barcode from one of said first non-machine-readable state and said second non-machine-readable state to said machine readable state. 